An example of a device which combines a fuel filter and a fuel pressure regulator is shown in U.S. Pat. No. 5,078,167. Such a device is adapted for mounting on what is sometimes called a fuel pump module. A fuel pump module typically fits in sealed manner to an opening in a wall of a fuel tank and contains an electrically operated fuel pump. Fuel that has entered the pump module from the fuel tank is pumped first through the combination pressure regulator/filter device and then through a conduit extending from the pump module to a fuel rail assembly on an engine. The fuel passing to the engine is filtered and pressure-regulated by the combination filter/pressure regulator device. An advantage of a device of this general type is that only a single fuel conduit is required between the fuel tank and the engine. In other words, a return conduit that returns excess fuel from the engine to the tank can be eliminated.
The device of U.S. Pat. No. 5,078,167 comprises a fuel pressure regulator that has as part of its internal mechanism a specially constructed chamber that senses the fuel pressure at the outlet of the device so that the pressure regulator can thereby compensate for any changes in pressure drop across the filter element, such as those which may occur due to clogging of the filter element over its useful life. Excess fuel is not pumped through the filter element, but rather falls back into the pump module before it ever reaches the filter element. The construction of that patented device is relatively complicated, comprising a number of individual parts that have to be assembled together so that the various functions can be performed in the manner described. Moreover, it appears that the patented combination device is not readily adaptable to fit varying packaging requirements for different automobile models.
A fuel pressure regulator/fuel filter module that is less complicated to assemble and that is more readily adaptable to different packaging requirements would be an improvement on the patented combination fuel filter/fuel pressure regulator. The present invention relates to such a module in which a self-contained fuel pressure regulator is assembled to the module thereby avoiding the need to integrate the fuel pressure regulator's internal mechanism internally into the module, as is done in the patented device. Moreover, by mounting the self-contained fuel pressure regulator on the exterior of the module by means of a separable attachment, it is possible to conveniently install and remove the pressure regulator on and from the module as a self-contained unit. Furthermore, the use of a self-contained fuel pressure regulator offers the potential for its use as a common component of different module models needed for various packaging requirements, and this promotes manufacturing economy because of economies of scale.
Additional features, advantages, and benefits of the present invention will be seen from the ensuing description that is accompanied by claims and drawing figures and illustrated in a presently preferred embodiment according to the best mode contemplated at this time for carrying out the invention.